Patent Document 1 identified below exists as an example of background art information relating to this type of container. In the case of the container disclosed in this Patent Document 1, when the bottom face of the container is pressed from above with the container under a posture of orienting the lid member downwards being set to a bottom portion of a setting space present upwardly of a dilution bottle, the pressure inside the container body increases to cause detachment of a portion of the annular seal portion from the flanged face, whereby the contents are discharged into the dilution bottle.
Therefore, if a liquid of concentrated beverage ingredient is used as the contents of the container, beverage of an appropriate concentration can be obtained by introducing water or the like into the dilution bottle.
Further, in the case of Patent Document 1, the lid member is sealed over a relatively large area extending along the flanged face entirely in its width direction. And, at a portion of the flanged face located at its radially inner edge, a sharp projecting portion projecting towards the radially inner side is provided as an exfoliation guiding portion.